Internal-combustion engine



i 12 192 Aprl 7 E. R. BURTNETT INTERNAL COMBUSTION ENGINE Filed Jhne 9, 1924 Patented Apr. 12, 1927.

UNITED STATES PATENT OFFICE.

EVERETT R. BURTNETT, OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO THE AUTOMO- TIVE VALVES (10., OF LOSANGELES, CALIFORNIA,'A VOLUNTARY TRUST.

INTERNAL-COMBUSTION ENGINE.

Application filed June 9, 1924. Serial No. 718,836.

My invention relates to a firing unit two 7 stroke cycle internal combustion-engine, the principal objects being, to provide an engine having multiple cylinders, arranged so that the combustion chamber pistons'are located as close to the poweroutput end of the crank shaft as possible, so as to reduce the axial length of that portion of the crank shaft through which the power is transmitted and 10 thereby materially reducing crank shaft whip and twist; and to provide the engine crank shaft with four main bearings, so arranged with respect to the cranks of said crank shaft, that there will be a decided ad- 1 vantage in crank shaft support withrespect to the Variation in the combustion and pump ing influences.

Further objects of my invention are to provide a six cylinder two stroke cycle en- 2 gine, in which four of the cylinders are adapted to combustion. and two of the cylinders to charge pumping to said combustion cylinders, the four combustion cylinders with the axis of the crank shaft and to pro-.

vide a crank bearing between each two cylinders;-to arrangethe cranks of the crank shaft to which the two forward pumping cylinders are connected, 180 apart, with the cranks to which the two pairs of combustion pistons are connected, arranged 180 apart, to connect the two pistons within the mem' bers of each pair of combustion cylinders, to one crank, the two cranks to which the two pairs of combustion pistons are connected being disposed circumferentially 180 apart with respect to each other, and the crank to which the piston of the first pump cylinder first from, either end of the row of cylinders being disposed substantially 180 circumferentially from the crank to which the'pair of pistons ofthe first pair of comhustion cylinders from the same end are connected.

' Further objects of my invention are, to arrange in an engine of the character described, a gaseous fuel transfer passage from the clearance chamber of each pumping cylinder to transfer inlet ports that are formed in wall of one of the pair of combustion cylinders that have their pistons connected to the crank that is diametrically opposite to the crank to which the respective pumping cylinder piston is connected and, to provide the cranks to which the pistons in the combustioncylinders are connected, with counter-balancing weights, each of the latter being located on the crank pins between the bearings for the corresponding pair of connecting rods.

With the foregoing and other objects, in view, my invention consists in certain novel features of construction and arrangement of parts that will be hereinafter more fully described and claimed and illustrated in th accompanying drawings in which Fig. 1 is a top plan view of an internal combustion engine embodyingithe principles of my invention.

' Fig. 2 is a vertical section taken lengthwise through the center of the engine and as indicated by line 2'2 of Fig. 1.

Fig. 3 is a diagrammatic View that graphicalljy; represents the relative ositions of the cran s of the crank shaft, when the pistons are in the positions as seen in Fig. 2.

Referring by numerals to the accompanying drawings,10 designates a cylinder block,

preferably cast in a single piece arid having formed therein six bores or cylindrical chambers. These bores are arranged in a straight row, with their axes parallel and occupying the same plane.

The first and second chambers 11 and 12 from the forward end of the block, function as gaseous precompression and pumping chambers, While the third and fourth chambers 13 and 14, constituting a pair, function as combustion chambers and the fifth and sixth chambers 15 and 16, constituting a pair, function as combustion chambers.

The walls of block 10 surrounding the chambers therein are formed with communieating chambers 17, through which may be circulated a fluid-coolingmedium, such as water.

Cylinder block 10 surmounts a suitably formed crank case 18, having main bearings 19 and secondary intermediate bearings 20 for a crank shaft 21.

This crank shaft has four throws or cranks that are designated respectively, by numerals 22, 23, 24 and E2.

Crank 22 is located in line with the axis of chamber 11 and connecting said crank with a piston 26 that is arranged for operation in said chamber 11 is a connecting rod 27.

Crank 23, which is arranged 180 or diametrically opposite to crank 22, is located in line with the axis of cylinder 12 and a connecting rod 28 connects said crank 23 and a piston 29 that is arranged for operation within said cylinder 12.

Crank 24:, which is of sufficient length to accommodate two connecting rods, is arranged in line with the axis of combustion chambers 13 and 1a and said crank 24: occupies the same radial plane with crank 23 and diametrically opposite to or 180 from crank 22.

Arranged for reciprocatory movement within chambers 13 and 14% are, respectively pistons 30 and 31 and connecting same with crank 24 are suitable connecting rods Crank 25, which is of sutlicient length to accommodate two connecting rods, is located in line with the axes of chambers 15 and 16 and said crank occupies the same radial plane with crank 22, that is diametrically opposite to, or 180 from cranks 23 and ill.

istons 33 and 3a are arranged for open tion respectively in chambers 15 and 16 and connecting said pistons with crank 25 are suitable connecting rods 35.

Cranks 24 and 25 are provided with suitable counterbalanced arms such as 36, the same being arranged on the crank pins, between the bearings for the connecting rods that are connected to said cranks.

These counterbalanccs are provided in order to counteract and eliminate the centrifugal couple and consequent vibration that would otherwise develop during rotatlon of the crank shaft at high speeds:

Secured to the head end of cylinder block 10 and closing the head ends of all of the chambers in said block, is a cylinder head 37, having a cooling fluid circulation cl1amher 38 that may be in communication with chamber 17.

Formed in the under side of this head block are shallow recesses or pockets 39 and 40 that communicate respectively with pumping chambers 11 and 12 and form clearance chambers therefor.

Leading from clearance chamber 39 through the side of block 37 is a transfer outlet port ll that communicates with an externally arranged transfer duct 42' and the opposite end of the latter communicates with inlet ports 43 that are formed through the wall of block 10 and which lead to the intermediate portion of combustion chamber 13.

Leading from clearance chamber all) outward through the side of head 37 is a transfer outlet port a4 that communicates directly with one end of a transfer duct 45 and the opposite end of the latter communicates wlth a transfer inlet port 46, that leads through the wall of the cylinder block into the intermediate portion of combustion chamber 15.

Inlet ports 43 and 16 are located so that they are wholly uncovered only when pistons 30 and are at the lower or outer ends of their travel.

Formed through the walls surrounding the combustion chambers 14 and 16 and in a plane where they are wholly uncovered only when the pistons 31 and 31 are at the lower or outer ends of their travel are exhaust ports such as lT,-the same communicating directly with an exhaust pipe 18.

Formed in the under side of block 37 is a shallow recess 49, that connects and serves as a common clearance, compression and combustion chamberior chambers 13 and 14 and a similar recess 50 in the under side of block 37, connects and serves as a common clearance compression and combustion chamher for the chambers 15 and 16 Spark plugs 51 are seated in head 37, preferably at points above cylinders 13 and 15 and the inner ends of the electrodes of said plugs project into the clearance chambers 49 and 50.

Gaseous fuel from a suitable source of supply such as a carburetor 52 may be supplied to the pumping chambers 11 and 12 in any suitable manner, but I prefer to utilize means that include piston valves 53, there being one valve for each pumping cylinder and said valves being operated by suitable driving connections to admit gaseous fuel intothe pumping chambers for practically the full periods of the suction strokes of the piston within said chambers.

In the operation of my improved engine, as pumping piston moves outwardly in its cylinder, the corresponding valve 53 is opened to admit gaseous fuel into chamber 11 and on the inward stroke of this piston, the charge of gaseous fuel will be compressed in clearance chamber 41 and duct 42. As piston 26 approaches and passes high center, piston 30, in combustion chamber 13 approaches and passes low center, thereby uncovering inlet ,ports 43 to admit to said chamber 13 the precompressed charge of gaseous fuel and the latter in rushing upward through chamber 13, laterally through chamber -19 and downward through chamber 1 1 will drive before it the products of com- .bustion remaining in said chambers from the previously ignited charge and said prodceases and during the continual upward movement of said pistons, the trapped charge of gaseous fuel will be compressed in common clearance chamber 49. At the point of highest compression or as the pistons pass their high centers, the compressed fuel charge is ignited-by a spark produced between the inner ends of .the electrodes of thecorresponding plug 51 and the expansion following combustion of the ignited charge forces, the pistons downward on their power'stroke and the motion and power thus developed is transmitted through connecting rods 32 to the crank shaft.

Identically the same actions take place and the same results are attained as described, in pumping cylinder 12 and the pair of combustion: cylinders 15 and 16 and owing to the, relative arrangement of the cranks of the crank shaft, the induction, precompression transfer, compression and firing operations in the two sets of cylinders or engine units take place alternatel so that a practically' continuous flow 0 power is trans mitted to the crank shaft.

Inasmuch as the two sets of combustion cylinders are located immediately adjacent to each other and at thesame end of the cylinder block, the axial distance that the power has to travel through the crank shaft to the point where it is taken ofi, is minimized and, as the two cranks for the four power or combustion cylinders are disposed immediately adjacent to each other and said cranks are provided with centrally disposed counterbalancing weights, the centrifugal couple in this particular position of the crank shaft is minimized.

Further, in my improved engine vibration is minimized and, as the two cranks:

for the four power or combustion cylinders are disposed immediately adjacent to each other and said cranks are provided with centrally disposed counterbalancing weights,

the centrifugal couple in this particular portion of the crank shaft is minimized.

Further, ,in my improved engine, vibration is minimized and the desirable-smooth and between the three pairs of cylinders,

their pistons "and the connecting ro It will be understood that minor changes in the size, form and construction of the various parts of my improved internal combustion engine may be made and substituted for those herein described, without departing from the spiritof the invention,

the scope of which is set forth in the appended claim.

I claim as my invention:

The combination in a two stroke cycle internal combustion engine, of six cylinders, a piston within each of the six cylinders, a crank shaft, a separate connection between each piston and the crank shaft, the six cylinders being arranged in a row parallel with the axis of the crank shaft, a detachable cylinder head having a recess formed in its underside to connect as a common compression and combustion chamber, the first and second cylinders from a given end of the row of six cylinders, a second recess formed in the cylinder head to connect as a 1 from the same end, a third and a fourth recess formed in the underside of the cylinder head, said third and fourth recesses being located so as to register with and provide volume clearance chambers for the fifth and sixth cylinders in the row, there being four crank throws to said crank shaft, two of said crank throws having two bearing periphcries and the other two throws having single bearing peripheries, a counterweight extending from and diametrically opposite the crank throw between the two bearing peripheries of each of the two bearing crank throws, said two bearing crank throws being disposed diametrically opposite to each other, the two single bearin crank'throws being arranged diametrically opposite to each other, four main bearings supporting the crank shaft, one main bearing on each end of the crank shaft outside of the cranks, a third main bearing disposed between the pair of single bearing crank throws and one of the two bearing crank throws, the fourth main bearing disposed between thepair of two bearing crank throws, ports formed in the wall of each of the sixcylinders, two transfer ducts, one leading from the clearance chamber of the first cylinder at one end of the row of six cylinders to the ports formed in the third cylinder from the same end, the second'transfer duct leading from the clearance chamber of the second cylinder from the same end, to the fifth cylinder from the same end, the pistons within one pair of cylinders that are joined by the common clearance recess in the cylinder head being connected by separate connections to the two bearing peripheries of one of the two bearing crank throws of the crank shaft,

the pistons within the second pair of cylin- I ders joined by the second clearance recess.

in the cylinder head, being connected by separate connections to the other one of the two bearing crank throws, the two cranks to which the istons of the cylinders that are joined by t e transfer ducts being angularly disposed in relation to each other so as to cause the piston within the one cylinder of the pair of cylinders joined by :1 common clearance recess in the cylinder head, to move suflicicntly past crank cnd dead center to close the ports formed in said cylinder and cut off registration with the respective transfer duct as the piston within the other cylinder of the two by said transfer duct reaches top or head end dead center and ignition means located in each of the two recesses formed in the cylinder head and which connect the members forming the two pairs of combustion cylinders.

In testimony whereof I afiix my signature.

EVERETT R. BUR'INETT. 

